Machine for cutting sheet material



Sept. 12, 1933. J w DODD v MACHINE FOR CUTTING SHEET MATERIAL 4 Sheets-Sheet 1 Filed NOV. 1 9, 1929 I I I I II ll|lllll Ill lllllllllllllll Sept. 12, 1933. J. w. DODD 1,926,669

MACHINE FOR CUTTING SHEET MATERIAL Filed Nov. 19, 1929 4 Sheets-Sheet 2 Sept. 12, 1933.

J. W. DODD MACHINE FOR CUTTING SHEET MATERIAL' Filed Nov. '19, 1929 4 Sheets-Sheet 3 E) O O I l A r g 2 29 Ab J5J/4J6/ Q J s:

,J722/63Z20w Sept. 12, 1933. J. w. DODD MACHINE FOR CUTTING $HEET MATERIAL Filed NOV. 19, 1929 4 Sheets-Sheet 4 J6 J6 .37

zrlaniiil/l/l V////// I? I III/IIII/l/l/lllll :Patented Sept. 12,1193? j MACHINE Fort CUTTING sneer MATERIA John vv -noaa, Brookline, Mass 7 j l Application Novemberlil; 1 929 Serial No. 408,252. cciaim te: (01. 1645-54 My invention relates to machines for cutting sheet material; vparticularly poweroperated pa- 7 per'cutting shears, and it has for its object to provide an improved. machine of this class; T It is also an object of this invention to improve.

the construction and operation of machines of V.

the type shown and described in U." S. Patent No. 1,564,006 granted December 1st, 1925. v i In the machine of v the patent referred to the knife-carrying cross head has associated with it paper-engaging and clamping means frictionally controlled wholly by the knife-carrying cross head so asto movetoward the paper with the cross-head and engage the paper i i-advance of, the knife of the cross-head to clamp the paper immovably in position upon the bed of the machine thereby to hold it against displacementwhile the knife is operating upon it.

Also, in the maohineof the patent-referred to,

the paper-clamping means moved upwardly with the knife-carrying cross-head immediately upon" the start of the latter upon its upward movement -With the result that sometimes the ascending ing the first partof its upward movement;

7 My present invention has for its main object 2 to prevent this displacement of the'paper by the upward movement of the cross-head. and knife."

In a machine of this class constructed in aca for clamping the paper or other'sheet material in position while it is being cut isoperatedlito release the same after the knife. has made its cutting stroke and been moved upwardly out of; engagement with the paper that has been out; and this is one;of the,distinguishing features of' the-:presentinvention. 1 Other features and advantages of my invention are hereinafter pointed out, i I

In the accompanying drawings: i

with my invention. 1

Figure 2 is a, section on line Figure 3" is a side elevation of the machine shown in Figure 1; s v

cutting sheet material constructed in' accordance Figure dis a section on line-de i of Figure li.

Figure 5 is a section on line 5-5 of Figure '1. v:Figure 6 a front elevationg'of the clamping bar and some of the parts associated therewith.

Having reference to the drawings,- 1- represents the framerof. my improved machine for. cutting sheet material; said frame includingyrthe usual bed,ior work-rest 2, provided withxan adjustablegaugef3. Thebed 2 is madeupon its topside knife would displace or disarrange the paperldur-f cordance with my present. invention the means:

' the-machine; Figs-'1', 4 and 6.

Figure 1 is a, front elevation ofja ma'chineforo 2+2 'of Figure 1.'

of Wood, fibre or thelike 62co-operating with azkn'ife blade 4 fastened to across-head5' mounted-in vertical ways 6 on the-frame of the machine. fl i H At'its opposite ends the cross-head 5'ismade rwithtatransverse groove occupied by :a strip with horizontal slots '7 to receiverolls 8 carried by'slides19connected with the frame 1 with provision'for vertical movement by the usualmeans including guide-rolls 10' and cross bars rollsl2engaging the top side of the cross head 5; "At' their lower ends the slides 9 are pivotally connected with the upper ends of. pitmen 13 whose opposite ends are connected withl wrist' pins 14 provided at the opposite ends of the main shaft 15' of the machine. This main shaft 15 is driventhrough the usual means controlled by a hancl'lever 58 which is manually operated to start saidlshaft in motion, the latter being automatically stopped at the completion of each revo-- llmounted on'frame 1." The slides 9 also carry 1 lu'tion thereof'." Attheir upperendsjthe slides 9 areconnected as usual by a tie-rod 61 as shown in'Fig.1.- I Whenv thefshaft 15 is rotated it acts through the pitmenl-B, slides 9 and rolls ,8 and 12, to first lower and then raisethe cross-head; 5 said shaft 15 being automatically sto'ppedwith the wrist pins j 14, and crossj-h'ead; 5 atthe limit of their upward movement." l

is a clamp-bar '16 to the opposite. ends of which are fastened vertically disposed bars 1 7 sliclably mounted in ways 18" provided onthe frame of At their. lowerends the slide-bars lT-are 'se cure'djtothe oppositeends of across-bar 18, to the"uncler side ofwhich is pivotally connected, I

at 19, the upper end of a bail-shaped member 20. The bail-shaped member 20 provid'es'a' verticalfslot-2l that is occupied by the forwardly extending arms 22 and 23 of two levers.24 and 25 fulcr'uined, respectively, at 25; a n'd- 27,;upon

the frame of the machine;

Q The upper .lever 24, Fig.4," has arearwardly extending arm 28 on which is adjustably mounted a weight-29 suiiicient to act'through,l ver 24;

cross-barvlfi and slide-b ars "17, to *lifft "clam -ban a 16; whileEthe-lev'er 25 is also provided with arealp mounted 'aj'weight a a "Ihe "clamp-bar 16 is yieldingly urged upwardly wardly extending arm 30 on which is adjustably 7 toward, an abutment-bar 32" by the weight=29l 1 acting "through the connections described, the

' opposite ends 'of'. said; bar 32 being also slida-bly Immediately at therear of-the cross-head 5 59 to limitthe upward movement of the latter .bar 32. Inthisway-the pressures of the shoes which frictionally'clarnp the abutment-bar 32 to mounted in the machine.

In addition to thetwo arms 23 and the "lever 25 is made with a third arm' 59 provided at its forward free end with a foot-piece 33,

Figs. 1 and 4.] v l r The arm.59.'oflever 25 extends forwardly through a vertical slot 34 provided" in an approximately-.upright apron or plate forming part of the frame of the machine and the upper end of this slotfi l serves as a stopengaged by arm under the influence of the weight 31 the arm 23 Normally the free end portion of of lever 25 occupies a position within the slotl the above noted patent so that there is no tendency 21 of member 20-at the bottom end thereof and it will therefore be clear that when arm 23 is swung downwardly by foot pressure applied to arm 59, said arm 23 will act through member 20; cross-bar 18 and slide-bars l7 to move the-clampe barflfi downwardly into position ontop of the stack'of paper or the like that is to be; cut.

Thus means is provided through "which the yieldingly heldvelev'ated in'its nornial position I adjace'ntabutment-bar 32 by 'the weight 29 pre parat'ory, to the'toutting' opera'tions 'of' the ma-L chine.

The inner side'of the abutment-bar 32'is made with a recess 36, Fig.5 within whichisloosely mounted a friction shoe 3"], preferably made from wood, which is 'urgedrlaterally against "the rear 7 side of the cross-head 5 by" coiled s'prings 38. These two springs extend through holes 39;,formed through the abutment-bar 32 totheoutside'of, the latter where theyabut against a relatively 'sh ort' lpresser-bar 43.

:The abutment-bar32 a e with spa of holes through it in which are fixe d ithe shanks 10f two tubular studs ififthe shank of each' of said studs being of less diameter than its fora wardly extending body portion so as toprovidea shoulderthat is clampedagainstthe abutmentbar 32 by a nut the shank. 1

receive uponit nutse i against'which pressenbar .43 is held by the springs38; 1

. Atits forward end each pull-rod i2iextends beyond-its stud iO' 'thr ughfan aperture provided throughflthe adiaoent end of apush bar' 45 andis'provided'atits outer end withaliad 46 bearing fag'ainst't he outer side of said push; bar. v At its middle the push-bar" i5 is madewith a threadeda e ure to "receive an abutment screw 47 providedat its outer end withafihand wheel 48. At itsvinner, end this ahutment's crew'bears against a two-part friction shoe comprising amenu holder-member] r9 -rnade wijth a socket within which is seated a .v fooden friction vshoev 5D; Theseftwo rnembersiare Inadenear theirv ends with registering apertures to loosely receive the end portions of the tubular studs 40.'

Thestuds 40 extend through oblique slots 5 formedin the crossehe ad 5 and have loosely mounted upon them rolls :52 normally occupying positions near the lower ends-of vsaid slots; 1

ways l8 on the frame of the 5'? fast on the main'c'rank shaft 15.

il o'n'the threaded rearen'd of Within eaeiitupunr stud doisloosely mounted- 1,926,669 is I a .5 r. V

It will be clear that by adjustment of screw 47" the springs 38 may be compressed to the desired degree and their inner or front ends will force the f friction shoe 37 against the rear side ofthe crosshead 5 while their opposite ends act through bar 43, pull-rods 42,;push-bar 45, and screw 17 to force the friction shoe 49'501 against the opposite frontface of the cross-head. Thus the abutmentbar'32 is frictionally clamped toth'e cross-head 5 by which it is normally supported'by equal pressures exerted upon opposite sides thereof by the friction shoes that are carried by the abutmentthe oros's headfi are opposed and balanced as'in towarddistortion of the cross-head.

' The arm 22 of lever 24 which normallyoccupies the upper end of slot 21 of the member 20 has hole provided at the free, end of a lever 5 i'fu1- crumed amt-55 on the frame of'the machine and carrying a cam-roll 56 co-operatingwith a cam The lower end portion oflinlc53is threaded and provided with a pair of nuts '60 to co-operate with lever54.- J V f ywhenthe machine is started by the usual control lever'58, Fig. 1', the main crankshaft 15 makes ,onerevolution and stops and during this revolutionthe 'wrist pins 14' of shaft 1-5ffirst lower and then raise the cross-head 5 while at the same time thecam'5'7 is rotated to the. extent of one revolu 'During the downward'travelofc ross-head-5' the clampbar "i6 is simultaneously lowered by cam 5"! acting through lever 54, link 53 and'lever upon the-top c the-stack: or" paper on the bed 2. The cam-57 is shapedandtimed so that during than the"croS's-head 5; Thus after clamp-bar 16 comes to'rest upon the stack of paper on bed 2,

" arm-22; until the said clamp-bar comes to rest 7 this first part of t'lierev'olution of'shaft 15 the r anduntil the cutting edge of knife 4' reaches said stack; the said 'clamp mar is urged downwardly'by gravity so astoexert a preliminary pressure upon i downward pressur'e later tobe' enerted 'by said the stack'of paperthat is less than the maximum Continueddescentof the cross-headlo wers the s abutment-bar 32 into-engagement with the now --statio'na'r'y clamp-bar 16 before the cutting" edge of knife' reaches-thebottomof'clamp-bar lG-so that thereafter, while the cutting edge ismo'ving downtoward the'bottomof clamp-bar l6 and abutment-bar 32 is at rest on the latter, lan addi tional, but not yet maximum, downward pressure J -v is exerted by the clamp-barupon the paper stack because {of the frictional connection between the abutment bar 32 and cro'ss-head5 .andthe down-' ward pressureof theupper sides of slots 51 upon I rolls 52 on 'abutment ba'r 32. i T 1 7 V 'Duringthis downward movement of the crosshead after abutment-bar 32 comes torest on clamp bar 16 saidcross-h'ead is deflected 'endwise toward the leftQFig IJs that then the movement of 'the cross-head' is obliquely downward until it reaches the limit "of its downward j: movement.

This'oblique'moveinent starts assoon as'abuter ment-bar'32 comes to rest upon clamp-bar 516.; 1 when duringthe descent of the cr'osseheadthe n 1 cutting edgezof'the k nifegi engages the stack of 1213 1 paper on table 2; the resistance of the paper to the descent of the knife and cross-head re acts throu h the rolls 52, and abutment-bar 32 to cause the clamp-bar 16 to exert its maximum downward pressure upon the stack of paper so that thelatter is securely held against displacement while the knife is forced thereth'rou'gh.

The cam 5'? is timedto maintain the arm 22 de-- pressed for about three-quarters of the revolution of shaft 15 so that during the last quarter of the revolution of said shaft the arm 22-is raised by the weight 29. Thus the cam 57 delaysthe-start-of the upward movement of clamp-bar 16 underthe influence of weight 29 until after the knife blade 4 has been raisedby wrist pins'le sufliciently to carry it out of engagement'with the work on the Inthis way Iprevent the displacement:

table 2; of the paper or other work on table 2 by the upward movement of the blade 4. t

At the start of the upward movement of the cross-head 5 the abutmentebar 32, because of its frictional connection with saidcross-head, moves upwardly with the latter, but before the cross- T to Cir

' ally connected with said cross-head so as "to behead reaches the limit of its upward movementa spring 58 carried by said abutment-bar comes into position against a stop 63 on the frame ofthe" machine thereby yieldingly stopping further upward movement of'the abutment bar s'othat thereafter thecross-head 5 continues its upward move-v ment alone. During the periodof-time between theengagement of spring 58 with the stop 63 and the completion of the upward movement of crosshead 5, the slots 51 co-actwith rolls'52 to return said cross-head to its position at the limit of its movement toward the right, Fig. 1. WhatIclaimis: w i J 1. A machine for cutting sheet material comprising a knife-carrying cross-head; means including a main shaft for reciprocating said crosshead vertically with provision for movement thereof endwise also; an abutment-bar'frictionmoved vertically by the latter; a vertically movable clamp-bar' beneath said abutmentabar serving through its engagement with the work to stop the downward movement of said abutment-bar with the cross-head; means yieldingly supporting said clamp-bar; means through which said'abutment-bar acts to deflect said cross-head endwise l in one direction when the downward movement of said abutment-bar with "the cross-head lis arrested by the clamp-bar; a stop to limit the upward movement of said abutment-bar with said cross-head; means through which said abutmentbar acts to;deflect saidcross-headendwise in the oppositedirection when the upward movement of i said abutment-bar is arrested by said stop, and a cam on said main shaft operating at thestartof. 7

the upward movement or the cross-head to maintainlsaid clamp-bar in engagementwith thework until after the knifeof the cross-head has been moved upwardly out of engagement with said work. I

main shaft; a cam on said main "shajt; alever to-raise and lower said clamp-bar; 1

'2 Amachine for cutting sheet material 0011- structed in accordance with claim 1 wherein the,

said cam .controls the means forfyieldingly supporting said clamp-bar to maintain the latter in engagement with the work until after the knifeof the cross-head has been moved upwardly out of engagement'with said work. r .3. In a machine of the char acterdescribed the" combination of a vertically movable clamp-bar structure; a lever, having one arm thereof in abutting engagement with said clamp-bar struc ,ture; a weight constituting par'tof the other arm or saidlever and operating through the "latter to v support-said clamp-bar in an elevated position; a

operated by said cam, and a link connecting said. two levers through. which said cam and its lever" act toadjust said first-mentioned lever thereby 4. Af'machine of the character described constructed in accordance with claim 3 wherein with 'said' cross-head; a lever having one arm thereof in abuttingengagement with said clamp-1 bar structure and another arm provided with a weight by which said lever is caused to support t saidclamp-bar in an elevated position; a foot operated lever having anarm thereof co-operatw ing with said clamp-bar structurea cam onsaidshalt; means connected with said first-mentioned: lever through which said cam operates the same thereby to raiseand lower said clamp bar structure independently of said foot-operated lever and in timed relation with the movements of said cross-head. g e I 6. Amachine of the character-described comprising a movably supported knife-carrying cross:

head; a work-rest; means by whichsaid crosshead is moved toward and from said work-rest;

workeclamping means associatedwith said crosshead and movableftoward. and from saidwork-"z rest; means for shifting said work-clamping means toward and against the work'on'said work-t rest'asgsaid cross-head is moved toward said .work- I rest but at greater speed than'that'at which said cross-head is then moved; means through which is said cross-head acts to holdsaid work-clamping .1

means against the work while the latter is beingv cut, and means for, moving. said work-clamping -means away from said work-rest after saidcross-, head has been moved away from the latter farenough to disengage itsknife from thework.

' JOHN WJDO DDQ 

